[order] Anseriformes | [family] Anatidae | [latin] Lophodytes cucullatus | [UK] Hooded Merganser | [FR] Harle couronné | [DE] Kappensäger | [ES] Serreta Capuchona | [IT] Smergo dal ciuffo | [NL] Kokardezaagbek

Kokardezaagbek determination

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At 40-49 cm, the Hooded Merganser is the smallest North American merganser. Exact weights have not been documented. Like all mergansers, it has a long, narrow, serrated bill. It has a brownish-black back and wings, with a white underside. The male has a black head with a white, fan-shaped crest, which is bordered in black. The males iris is bright yellow, while the iris of females and immature males is duller brown.

The Hooded Merganser nests in forested wetlands throughout its range. Some records show nesting in man-made boxes on grasslands and in nonforested wetlands. The kind of forest used for nesting varies from spruce/fur to cottonwood/elder and oak/cypress/tupelo, depending on the geographic location. In the winter they seek out shallow, freshwater and brackish bays, estuaries, and tidal creeks and ponds.

The Hooded Merganser breeds throughout the Pacific Northwest of the United States, across southern Canada, and east of the Mississippi. It is largely concentrated in forested regions around the Great Lakes. Wintering ranges include an area along the Pacific Coast of California, and a second area of coastal habitats from Delaware through Texas. Although the Hooded Merganser is mostly aquatic and awkward on land, females lead their ducklings up to 1.2 km across land from inland nests in order to reach water. Hooded Mergansers are clumsy, but quick, flyers. They take off by running on water, and they have a ceaseless and rapid wingbeat during flight. They land at high speeds and are often seen 'skiing' across the water to come to a stop. They dive well, holding their wings in close to their body and propelling themselves underwater with their feet. They have been seen gathering at roost sites in large groups during the nonbreeding season. Little is known about their territoriality during the breeding season.

Hooded Mergansers feed in clear aquatic habitats, such as forested ponds, rivers, streams, and flooded forests. Their primary foods include aquatic insects, fish, and crustaceans.

This species has a large range, with an estimated global Extent of Occurrence of 5,500,000 km². It has a large global population estimated to be 270,000-390,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.
At the turn of the century, Hooded Mergansers were largely overhunted. Today, however, they are not a prized sport species. Habitat degradation is now a more pressing concern for their conservation. River channalization, deforestation, and agricultural practices have caused an increase in loose sediment and turbidity, reducing the available habitat for the Hooded Merganser. Also, acid rain has the potential to harm the species, because a low pH can cause a significant reduction in aquatic invertebrates. A diminished food supply would reduce the growth of young ducklings. There is no informaton on the exact population size, and the Hooded Merganser has no special conservation status. In the future, care must be taken to preserve the cavity producing trees and forests which these birds depend on. [conservation status from birdlife.org]

Females select the nest site, which is usually a cavity in a dead or live tree. Nest boxes, along with already built and abandoned nest sites, are preferred. Cavities are usually 4-15 feet off the ground. Between 7 and 15 eggs are laid shortly after the nest is completed, from late February through early June, depending on latitude, although most breeding occurs in March and April. Incubation begins after all the eggs have been laid. The male abandons the female shortly after this point. The female incubates for nearly one month, during which time she loses 8-16% of her body weight. After the ducklings hatch they usually leave the nest within about 24 hours. Females brood eggs in the nest and care for young after hatching. Males leave the female soon after egg incubation begins. Young hooded mergansers leave their nest within 24 hours of hatching and are able to feed and dive immediately upon emergence from the nest. There is little information on parental care after hatching. One female abandoned her brood 5 weeks after hatching.

Forested wetlands, brackish estuaries and tidal creeks are preferred wintering habitats. Hooded mergansers winter along the Pacific, Atlantic, and Gulf coasts, mainly from southeastern Alaska to northern Baja California, and New England to Florida and west to northern Mexico. The majority of wintering hooded mergansers occur in the Mississippi Flyway.